'Shab-e Yalda', celebrated on 21
December, has great significance in the Iranian calendar. It is the eve of the
birth of Mithra, the Sun God, who symbolised light, goodness and strength on
earth. Shab-e Yalda is a time of joy.

Yalda is a Syriac word meaning birth.
Mithra-worshippers used the term 'yalda' specifically with reference to the
birth of Mithra. As the longest night of the year, the Eve of Yalda (Shab-e
Yalda) is also a turning point, after which the days grow longer. In ancient
times it symbolised the triumph of the Sun God over the powers of darkness.

The Cult of the Sun was first
introduced to Iran thousands of years ago by migrant Aryans. Mithra, the Sun
God remained a potent symbol of worship throughout the following centuries.
Centuries later, during the Achaemenid era, Mithra became a principal deity,
equal in rank to Ahura Mazda (the god of all goodness) and Anahita (goddess of
water and fertility).

In Sasanian times, Zoroastrianism
became Iran's official religion, but Mithra's importance remained
undiminished. This is evident from the bas-reliefs as Naqsh-e Rustam and Tagh-e
Bustan. At Naqsh-e Rustam, Anahita bestows the royal diadem upon Nasri, the
Sasanian King. At the investiture of Ardeshir I, Ahura Mazda bestows this
diadem to the new King. At Tagh-e Bustan too, Ahura Mazda is again conferring
the royal diadem upon Ardeshir II. Mithra is always present as a witness to
these ceremonies.

Over the centuries Mithraism spread
to Greece and Ancient Rome via Asia Minor, gaining popularity within the ranks
of the Roman army. In the 4th century AD as a result of errors made in
calculating leap years and dates, the birthday of Mithra was transferred to 25
December. Until then Christ's birthday had been celebrated on 6 January by all
branches of the Christian Church. But with the cult of Mithra still popular in
Roman Europe, the Christian Church adopted many of the Mithraic rituals and
proclaimed 25 December as the official birthday of Christ. Today the Armenian
and Eastern Orthodox Churches continue to celebrate 6 January as Christ's
birthday.

It was said that Mithra was born out
of the light that came from within the Alborz mountains. Ancient Iranians
would gather in caves along the mountain range throughout the night to witness
this miracle together at dawn. They were known as 'Yar-e Ghar' (Cave Mates).
In Iran today, despite of the advent of Islam and Muslim rituals, Shab-e Yalda
is still celebrated widely. It is a time when friends and family gather
together to eat, drink and read poetry (especially Hafiz) until well after
midnight. Fruits and nuts are eaten and pomegranates and watermelons are
particularly significant. The red colour in these fruits symbolises the
crimson hues of dawn and glow of life, invoking the splendour of Mithra.

Because Shab-e Yalda is the longest
and darkest night, it has come to symbolise many things in Persian poetry;
separation from a loved one, loneliness and waiting. After Shab-e Yalda a
transformation takes place - the waiting is over, light shines and goodness
prevails.

' The sight of you each morning is
a New Year
Any night of your departure is the eve of Yalda' (Sa'adi)

'With all my pains, there is still the hope of recovery
Like the eve of Yalda, there will finally be an end' (Sa'adi)